If so, it must have been due to some of our (pre-human) ancestors spending a lot of time in water, to the extent that those whose hands & feet didn’t wrinkle were definitely disadvantaged. SMH takes up the story (btw the word “purpose” is inappropriate here, because they’re talking about a naturally selected function):
>Getting “pruney fingers” from soaking in the bath is an evolutionary advantage, because it helps us get a better grip on objects under water, scientists suggest.
Digit puckering was long thought to be caused by a swelling of the outer layers of skin on the fingertips and toes, but recent research showed it was actually a nervous system response to immersion in water.
The purpose, though, was a mystery.
A team from the Institute of Neuroscience at Newcastle University in Britain tested the usefulness of wrinkling by human volunteers handling wet objects with creased and un-creased fingers.
Advertisement Those who had their hands immersed in warm water for 30 minutes were much faster than those with dry digits in a test that entailed picking up glass marbles and lead fishing weights between the thumb and index finger and transferring them from one container to another.
“We have shown that wrinkled fingers give a better grip in wet conditions,” research leader Tom Smulders said of the findings.
“It could be working like treads on your car tyres which allow more of the tyre to be in contact with the road and gives you a better grip.”
Read more: http://www.smh.com.au/technology/sci-tech/science-gets-a-grip-on-finger-wrinkles-20130110-2chgv.html#ixzz2HWWa5RQ9